Robert De Niro, Diane Keaton in wedding film

The actor will co-star with Diane Keaton in Gently Down the Stream as one half of a long-divorced couple forced to pretend they are still together for their adopted son on his wedding day, Variety reports.

Zackham said: "I'm excited to be able to continue what we started with on Bucket List – iconic actors in a funny, adult, character-driven story, albeit with a little more sex and bad behavior on everyone's part."